How much HP do we really Have
09-03-2014, 12:48 AM
#18
It's not rocket science and they aren't doing anything new. DCT's have been around for years and power is power. The hp rating just happens to be underrated from the factory. The only thing the car does for the driver in a quarter mile situation is allows for maximum trap speeds very easily with repeatable launch control and shifting. The horsepower/weight/trap speed figures are usually pretty accurate given an accurate trap speed and weight
Now, that doesn't account for the fact that the car probably feels like it has a bit more hp because of lightning fast shifts.
09-03-2014, 01:05 AM
#19
Race Director
Agreed, but DCT's haven't been around as long as those calculations (50's and 60's). Going from at least 250ms in a manual car to 8 ms per shift x 2-3 shifts to get to a quarter mile makes a huge difference in the values, and certainly shifts the curve. Add .5 to .75 of a second to the official quarter mile numbers and the calcs are more accurate.
Now, that doesn't account for the fact that the car probably feels like it has a bit more hp because of lightning fast shifts.
Now, that doesn't account for the fact that the car probably feels like it has a bit more hp because of lightning fast shifts.
It is interesting though the way this conversation has shifted (no pun intended) from the early days of this forum when a few people, who shall remain nameless, argued incessantly that PDK made absolutely no difference in terms of the car's performance. In retrospect, that seems pretty ridiculous....heck it was ridiculous at the time.
09-03-2014, 01:24 AM
#20
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I think you may be exaggerating the difference to some extent. When I ran 1/4's in my 440cid Plymouth GTX back in the day I would flat shift; somewhat abusive but pretty effective at keeping the wheels powered. Besides, quicker shifts may affect ET's but I don't think they have as much impact on trap speeds. ToyGuy, maybe you can chime in with some experienced comment on that.
It is interesting though the way this conversation has shifted (no pun intended) from the early days of this forum when a few people, who shall remain nameless, argued incessantly that PDK made absolutely no difference in terms of the car's performance. In retrospect, that seems pretty ridiculous....heck it was ridiculous at the time.
It is interesting though the way this conversation has shifted (no pun intended) from the early days of this forum when a few people, who shall remain nameless, argued incessantly that PDK made absolutely no difference in terms of the car's performance. In retrospect, that seems pretty ridiculous....heck it was ridiculous at the time.
09-03-2014, 01:40 AM
#21
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09-03-2014, 02:36 AM
#22
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About what I guessed it to be
09-03-2014, 02:53 AM
#23
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There is no way you guys are putting around with 475. My car with the power kit is not 430, I think its closer to 450+. I drove a 991S and the power kit is alot more than 30HP, Which makes me believe you guys around 500+ at least. And after seeing the sabine video has to be over 500.
Now we all know Porsche underestimates the HP figures for their cars to appear conservative. But the also, do so for insurance purposes also.
Has anyone done a baseline?
Now we all know Porsche underestimates the HP figures for their cars to appear conservative. But the also, do so for insurance purposes also.
Has anyone done a baseline?
09-03-2014, 03:14 AM
#24
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09-03-2014, 08:30 AM
#25
I think you may be exaggerating the difference to some extent. When I ran 1/4's in my 440cid Plymouth GTX back in the day I would flat shift; somewhat abusive but pretty effective at keeping the wheels powered. Besides, quicker shifts may affect ET's but I don't think they have as much impact on trap speeds. ToyGuy, maybe you can chime in with some experienced comment on that.
09-03-2014, 09:12 AM
#26
Race Director
I do believe PDK-S has a little some thing to do with its quick shifts and gearing. I still think the GT3 is more than 475 HP but the PDK-S helps its sprints
09-03-2014, 01:59 PM
#27
Burning Brakes
I thought some of you might be interested in the following link:
www.stealth316.com/2-calc-hp-et-mph.htm
You can pick any of the performance data that's been published for 1/4 mile speed, Et, Weight, Hp and play around with the formulas and see what you end up with for rear wheel HP.
I have seen weights ranging from 3135 to 3153. You would need to add in the weight of driver and a minimum of gas.
I have seen 1/4 mile speeds in the 125/126 range, and ETs in the 11.2s.
There are a lot variables that come into play in an actual car test. Most of these are small as compared to weight and HP. They will produces variances from the prediction however.
Nonetheless these mathematical models of performance suggest we may have significantly more HP than 475.
Remember, This is just for fun.
www.stealth316.com/2-calc-hp-et-mph.htm
You can pick any of the performance data that's been published for 1/4 mile speed, Et, Weight, Hp and play around with the formulas and see what you end up with for rear wheel HP.
I have seen weights ranging from 3135 to 3153. You would need to add in the weight of driver and a minimum of gas.
I have seen 1/4 mile speeds in the 125/126 range, and ETs in the 11.2s.
There are a lot variables that come into play in an actual car test. Most of these are small as compared to weight and HP. They will produces variances from the prediction however.
Nonetheless these mathematical models of performance suggest we may have significantly more HP than 475.
Remember, This is just for fun.
with the new Engine than the previous Engine, and higher than my previous tuned
996 Turbo Dynoed at close to 500 HP. The 0 to 60 MPH Times and 1/4 mile times, astonishingly to me, are almost identical to the 560 HP TTS Times. I understand the TTS is heavier, but IMHO we are making AT LEAST 500 Engine HP.
https://rennlist.com/forums/991-turb...other-day.html
09-03-2014, 02:04 PM
#28
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6 . NET POWER MEASUREMENT TOLERANCES
6.1 . The net power of the engine as determined by the technical service may differ by v ±2 % from the net power specified by the manufacturer, with a 1 - 5 % tolerance for the engine speed.
6.2 . The net power of an engine during a production conformity test may differ by ± 5 % from the net power determined in a type-approval test.
CARB/EPA also has some allowances for mileage and maximum power variances of ±6% (i forget which EPA database I found the Porsche certifications in that gave the number -- if I come across them again I will post them).
09-03-2014, 02:15 PM
#29
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